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The present invention relates generally to the field of Micro-ElectroMechanical Systems (MEMS), and more specifically to MEMS devices that can be easily configured to provide extended ranges of rotational and/or translational motion.
MEMS devices have been widely employed as actuators or sensors in various micro-electromechanical applications including inkjet printers, read/write heads in computer disk drives, accelerometers, and pressure sensors. More recently, MEMS devices have been employed in optical networking applications including optical cross-connect modules for controlling switching between optical fiber input and output ports. For example, such optical cross-connects typically comprise two or three-dimensional arrays of optical mirrors configured to direct pluralities of beams of light from selected sets of fiber input ports to selected sets of fiber output ports. Further, conventional MEMS devices included in such optical cross-connects are configured to move at least some of the optical mirrors in the array under computer control to bring about a desired switching between the selected sets of fiber input and output ports.
MEMS devices employed in today""s optical networking applications are frequently called upon to satisfy demanding performance requirements. For example, such MEMS devices are often required to move relatively large structures (e.g., optical mirrors, prisms, or optical gratings) over relatively large distances with high speed and a high degree of precision. However, conventional MEMS devices used in optical networking applications typically impart only limited ranges of linear or angular displacement. Further, such conventional MEMS devices are typically only capable of causing structures to rotate about a single axis.
It would therefore be desirable to have MEMS devices that can be employed as actuators or sensors in micro-electromechanical or micro-opto-electromechanical applications. Such MEMS devices would be easily configured to provide extended ranges of rotational and/or translational motion. It would also be desirable to have a MEMS device that can cause a structure such as an optical mirror to rotate about more than one axis.
In accordance with the present invention, a plurality of MEMS devices is provided that can be easily configured to impart extended ranges of rotational and/or translational motion. Benefits of the presently disclosed invention are achieved by providing a micro-electromechanical building block, one or more of which can be used to construct a respective MEMS device capable of moving a desired angular and/or linear distance.
In a first embodiment, the micro-electromechanical building block includes at least one bendable member having a first end connectable to a support structure, and at least one straight rigid member having a first end connected to a second end of the bendable member. In the event the bendable member is in a straight condition, the rigid member extends from the second end of the bendable member toward the support structure. Further, the bendable member has a predetermined length, and the rigid member has a length within a range from one half to the full predetermined length of the bendable member to allow a free end of the rigid member to undergo extended rotational and/or translational motion in response to a displacement of the bendable member.
In a preferred embodiment, the support structure comprises a frame of silicon, the bendable member comprises a length of silicon having regions with depositions providing bender or piezoelectric morph functions when energized with a voltage, and the rigid member comprises a rigid silicon bar. The support structure, the bendable member, and the rigid member are formed from the same silicon wafer by way of a silicon micro-machining fabrication technique.
In further embodiments of the present invention, at least one micro-electromechanical building block comprising at least one bendable member connectable to at least one straight rigid member is used to construct respective MEMS devices capable of moving desired angular and/or linear distances.
A first MEMS device includes a first bendable member having a first end connectable to a support structure, and a first straight rigid member having a first end connected to a second end of the first bendable member. In the event the first bendable member is in a straight condition, the first rigid member extends toward the support structure. The first MEMS device also includes a second bendable member having a first end connected to a second end of the first rigid member, in which the first and second bendable members are configured to undergo respective displacements in a same direction; and, a second straight rigid member having a first end connected to a second end of the second bendable member. In the event the first and second bendable members are in respective straight conditions, the second rigid member extends toward the support structure. The first and second bendable members have the same predetermined length. Further, the first rigid member has a length equal to the predetermined length of the first and second bendable members, and the second rigid member has a length equal to one half of the length of the first rigid member to allow a free end of the second rigid member to undergo a pure rotation in response to a displacement of at least the first bendable member.
A second MEMS device includes a first bendable member having a first end connectable to a support structure, and a straight rigid member having a first end connected to a second end of the first bendable member. In the event the first bendable member is in a straight condition, the rigid member extends toward the support structure. The second MEMS device also includes a second bendable member having a first end connected to a second end of the rigid member. In the event the first and second bendable members are in respective straight conditions, the second bendable member extends away from the support structure. The first and second bendable members have the same predetermined length, and are configured to undergo respective displacements in opposite directions. Further, the rigid member has a length equal to one half of the predetermined length of the first and second bendable members to allow a free end of the second bendable member to undergo a pure translation in response to a displacement of at least the first bendable member.
A third MEMS device includes a first bendable member having a first end connectable to a support structure, and a second bendable member having a first end connected to a second end of the first bendable member. In the event the first and second bendable members are in respective straight conditions, the second bendable member extends away from the support structure. The first and second bendable members have the same predetermined length, and are configured to undergo respective displacements in opposite directions to allow a free end of the second bendable member to undergo a pure translation in response to a displacement of at least the first bendable member.
A fourth MEMS device includes a first bendable member having a first end connectable to a support structure, and a first straight rigid member having a first end connected to a second end of the first bendable member. In the event the first bendable member is in a straight condition, the first rigid member extends toward the support structure. The fourth MEMS device also includes a second bendable member having a first end connected to a second end of the first rigid member. In the event the first and second bendable members are in respective straight conditions, the second bendable member extends toward the support structure. The fourth MEMS device also includes a second straight rigid member having a first end connected to a second end of the second bendable member. In the event the first and second bendable members are in respective straight conditions, the second rigid member extends away from the support structure. The first and second bendable members have the same predetermined length, and are configured to undergo respective displacements in a same direction. Further, the first and second rigid members have respective lengths equal to one half of the predetermined length of the first and second bendable members to allow a free end of the second rigid member to undergo a pure translation in response to a displacement of at least the first bendable member.
By employing at least one micro-electromechanical building block to construct a plurality of MEMS devices, respective MEMS devices capable of moving desired angular and/or linear distances can be easily configured. Further, the respective MEMS devices can be employed as actuators or sensors in a variety of micro-electromechanical and micro-opto-electromechanical applications.
Other features, functions, and aspects of the invention will be evident from the Detailed Description of the Invention that follows.